The present invention relates to a kick down control kick down control system an automotive engine, and more particularly to a system for detecting a maximum opening degree of a throttle valve.
In an automatic transmission, kickdown is performed in accordance with a kickdown signal which is produced from a kickdown switch. The kickdown switch is provided on a throttle valve body for producing the kickdown signal at a wide-open throttle position (full throttle).
However, in order to turn on the kickdown switch at the full throttle position, the kickdown switch must be located at an accurate full throttle position. Such an installation for the switch requires a plurality of steps of working which result increases the cost for the transmission.
In order to solve such a problem, it has been proposed to use an output signal of a throttle position sensor as a kickdown signal when the output signal exceeds a predetermined valve.
However, a delay of timing of the of kickdown operation occurs due a time variance of the throttle position sensor, caused by manufacturing tolerances.